The present invention relates to heart valve treatment and, in particular, to mitral valve leaflet repair and left atrial appendage closure. More particularly, the present invention relates to devices and methods for treating both the mitral valve and the left atrial appendage.
Properly functioning heart valves can maintain unidirectional blood flow in the circulatory system by opening and closing, depending on the difference in pressure from one side of the valve to the other. The two atrioventricular valves (mitral and tricuspid valves) are multicusped valves that prevent backflow from the ventricles into the atria during systole. They are anchored to the wall of the ventricle by chordae tendineae, which prevent the valve from inverting.
The mitral valve is located at the gate of the left ventricle and is made up of two leaflets and a diaphanous incomplete ring around the valve, known as the mitral valve annulus. When the valve opens, blood flows into the left ventricle. After the left ventricle fills with blood and contracts, the two leaflets of the mitral valve are pushed upwards and close, preventing blood from flowing back into the left atrium and the lungs.
Mitral valve prolapse is a type of myxomatous valve disease in which the abnormal mitral valve leaflets prolapse (i.e., a portion of the affected leaflet may be billowed, loose, and floppy). In one example, the chordae tendineae may stretch and thus become too long, or the chordae tendineae may be ruptured. As a result, the valve does not close normally and the unsupported valve leaflet may bulge back, or “prolapse,” into the left atrium like a parachute. Thus, as the ventricle contracts, the abnormal leaflet may be propelled backwards, beyond its normal closure line and into the left atrium, thereby allowing blood to return to the left atrium and the lungs.
Mitral valve prolapse causes mitral regurgitation. Isolated posterior leaflet prolapse of the human heart mitral valve, i.e., prolapse of a single leaflet, is the most common cause of mitral regurgitation. The exact cause of the prolapse may not be clear. Untreated mitral regurgitation may lead to congestive heart failure and pulmonary hypertension.
Located near the mitral valve is the left atrial appendage, a small pouch which empties into the left atrium. Under certain conditions, the heart may contract in an abnormal manner. When this happens, as will be explained in greater detail below, the left atrial appendage may be responsible for clot formation, which may cause a stroke.
There therefore is a need for further improvements to the current techniques for heart valve leaflet repair and/or replacement while minimizing the risk of stroke associated with the left atrial appendage. Among other advantages, the present invention may address one or more of these needs.